Prepayment-wattmeter for three-wire systems.



PATENTBD JUNE 30, 1903.

V G. G. TILDBN. PREPAYMENT WATTMETER FOR THREE WIRE SYSTEMS.

APPLIDATION FILED AUG. 1, 1901.

H0 MODEL.

INVENTOR 1* George G. JZZdew,

-4 ATTOR EY UNITED STATES Patented June 30, 1903.

PATENT OFFICE.

GEORGE G. TILDEN, OF NEWARK, NEW JERSEY, ASSIGNOR TO WESTING- HOUSE ELECTRIC dz MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

PREPAYMENT-WATTMETER FOR THREE-WIRE SYSTEMS.

SPECIFICATION forming part of Letters Patent N0. 7 32,139, dated June 30, 1903.

Application filed August 1, 1901. Serial No. 70,456. iNo model.)

To all whom it may concern.-

Be it known that I, GEORGE G. TILDEN, a

citizen of the United States, and a resident of Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Prepaymentattmeters for Three-Wire Systems, of which the following is a specification.

My invention relates to a novel arrangement of circuits for prepayment-wattmeters adapted for use in connection with three-Wire distribution systems.

I have illustrated my invention as being connected up in an alternating-current house or Working circuit having a derived or localized center or source of electrical energy connected with a standard wattmeter, say, of the Westinghouse type. \Vhen the house or working circuit is energized, the wattmeter is operated through the medium of the derived or localized source, and the consumption is reckoned by the period of time during which the wattmeter is thus operated.

By providing the moving parts of the wattmeter with suitable contacts I am able, through the act of depositing the proper coins in a suitable duct in the wattmeter, to start the house or working circuit into operation, to shift the cooperating-contacts symmetrically, so as to secure the same period of travel for the moving contacts after depositing each coin, and to insure the interruption of the house or Working circuit when it has consumed all the energy to which the deposit of the proper coin entitles the consumer. I can also so arrange the parts that within definite limits any number of coins can be successively deposited at about the same time without loss to the consumer of any part of the energy to which he is entitled.

The apparatus on which the wattmeter-contacts act, as above described, to start and stop the flow of current in the house or working circuit may be a small Westinghouse doublepole-brush type circuit-breaker.

-In the drawings which illustrate my invention, Figure 1 is a diagram of a system of circuits and apparatus adapted to accomplish the results described above, and Fig. 2 is a detail section along the line 2 2 in Fig. 1.

The circuit-breaker appears at l. and the wattmeter at 2, while the derived or localized source of energy appears at 3 as a converter with two primaries,lone in each of the outer legs 4 and 5, of a three-wire distribution system.

The house-circuitis normally open inside the circuit-breaker at the points 6 6 in the legs 4 and 5, the neutral wire '7 being carried through without interruption.

The brushes 8 8 of the circuit-breaker are pivoted at 9 9 and are connected at 10 10 with toggle-levers 11 11. The said levers are both joined at their inner ends to the central portion of a movable core 12, the ends of which lie Within solenoids 13 14. To prevent shortcircuiting, pieces of-insulation 15 15 are interposed between the inner and outer ends of the toggle-levers, as shown.

When the wattmeter is not in service, the normal position of the elements of the circuit-breaker is that shown in the diagram. The said elements are generally inclosed in a small cast-iron .case, conventionally shown at 1 and arranged relatively to the wattmeter at any suitable point.

The details of the wattmeter are not shown in the diagram, as no change in construction or arrangement is made necessary by the prepayment apparatus.

The slot for depositing a coin is shown at 16, this slot being the open mouth of a chute 17, extending downward into the wattmeter. In the path of the coin I interpose a lever 18,

with which a pawl 19 is connected. The said pawl 19 engages a ratchet-toothed wheel 20, and when the lever 18 is moved downward by the weight of a coin the pawl and ratchet act upon a spacing-wheel 21 on the same shaft with the ratchet and move the latter a fixed distance, which in the present instance is onetenth the circu niference of the spacing-wheel. When the coin has passed by the end of the lever 18, the said lever and the pawl attached thereto are restored to the normal position shown in the drawings by means of a spring 22.

Upon the periphery of the spacing-Wheel 21 are two contact-pieces 23 24, connected by wires 25 and 26 with terminals of the two solenoids 13 and 14. These contact-pieces are distant from each other one-tenth of the circumference of the spacing-wheel. The two remaining terminals of the solenoids are con-.

nected by wires 27 and 28, respectively, to clips 29 and 30, so arranged that one of the toggle-levers of the switch enters and remains in the clip 29 when the circuit is opened and is drawn out and thrown into the other clip 30 when the circuit is closed.

It will be understood that the connections between the con tact-pieces 23 24 and the wires 25 and 26, respectively, are so made as to permit the proper rotation of thesp'aciug-wheel carrying the said contact-pieces without tangling the wires. This can be accomplished by means of flexible connections or by any other appropriate means.

The period of consumption is measured by the movement of a small contact-spring 31, connected to the neutral wire 7 by a wire 32. The movement of the contact-spring 31 is derived from the counter 34 of the wattmeter, to which counter the spring 31 is attached through the medium of a pin 35.

The operation of the parts described is as follows: The consumer places a suitable coin, such as a twenty-five-cent piece, in the coinslot 16, and its passage through the coinchute 17 operates the lever 18, which turns the spacing-wheel 21 part of a revolution in the direction ofthe arrow. This movement brings the contact 23 under the spring-contact 31, thereby establishing the circuit of the solenoid 13 from the leg 4 over the switch 8, clip 29, and wire 27 to one terminal of the said solenoid. From the other terminal the circuit passes by wire 25 to the contact 23, spring-contact 31, and Wire 32 to the neutral wire 7. The energized solenoid 13 draws in its core and withdraws one of the togglelevers from the clip 29, causing it to enter the clip 30. The working circuit is thus established, and at the same instant the cir cuit of the solenoid 13 is opened at the clip 29 and at the spring-contact 31, the latter being due to the fact that the movement of the spacing-wheel 21 carries the contact 23 a little beyond the spring-contact 31. The movement of the spring-contact 31, derived from the counter of the wattmeter, is in the same direction as the movement of the spacing-wheel 21 produced by the coin in traversing the chute. Accordingly the said springcontact passes over the contact 23, but with out effect, since the toggle-lever of the switch or circuit breaker is out of the clip 29. When the spring-contact reaches the contact 24 on the spacing-wheel, the circuit of the solenoid 14 is established from the outer leg 4 and the switch 8 over the clip 30 and Wire 28 to one terminal of the said solenoid and from the other terminal by way of the wire 26 to the contact-piece 24 and thence by the springcontact 31 and the wire 32 to the neutral wire 7. The closure of this circuit energizes the solenoid 14 and returns the switch or circuit breaker to its original position, opening the working circuit at the points 6 6 and returning the toggle-lever to the clip 29, where it remains until another coin is inserted and the operation repeated. Inasmuch as every downward movement of the lever 21 produced by the action of a coin dropping through the chute 17 causes one-tenth of a revolution of vthe spacing-wheel, it is obvious that nine coins might be deposited one after the other in the mouth of the chute,simply allowing time for the spring to restore the lever after each deposit and that this could be done without the consumer being deprived or defrauded of any of the electrical energy or service to which the deposit of such a number of coins would entitle him. By varying the fractional part of a revolution which the deposit of a single coin would produce the number of coins which can be safely deposited in this way could be varied. In any case the proper instructions to the consumer on the delivery of the apparatus to him would insure him against loss in case he should wish to deposit successively a number of coins in the wattmeter for any reason whatsoever.

I may provide a hand-switch, as 33, in the house or working circuit to enable the consumer to break the said circuit independently of the coin apparatus and so stop the consumption of current at will.

In order that the apparatus in its operation may impose upon the wattmeteras little drag or extra load as possible, I generally make the contacts 23 and 24 project a little beyond the periphery of the spacing-wheel and so arrange the point of the spring-contact 31 that it will simply make contact with the parts 23 and 24 without bearing upon the spacingwheel itself.

The invention claimed is- 1. In a three-wire system of electrical distribution,a house or working circuit,a derived or localized source of energy having a generating element connected up in each of the outer legs of the said circuit, a wattmeter operated by the energizing of the said derived or localized source, a switch in the house-circuit for closing and opening the same, and a controlling-switch at the wattmeter for operating the first-named switch, the said controlling-switch being actuated in the first instance by a suitable coin and in the second instance by the action of the counter of the wattmeter. V

2. In a three-wire system of electrical distribution, a house or working circuit including a normally open switch or circuit-breaker, a pair of solenoids acting in opposite directions to close and open the said switch alternately, a derived source of energy having a generating element in each of the outer legs of the house or working circuit, a wattmeter having a coin-duct and being operated by the said source of energy, and circuits and connections whereby the dropping of a coin into the coin-duct alternately closes the circuit of the two solenoids between the neutral wire and one or the other of the outer Wires of the house-circuit.

3. In a three-wire system of electrical distribution, a house or working circuit having three wires, one of which is a neutral wire and the other two of which are mains with interposed normally open switches, a togglelever connected with each of the said switches and both united to a reciprocating core or armature, a pair of magnets or solenoids controlling the said core, and means operated by a weight outside the switch mechanism for controlling the said switch.

4:. In a three-wire system of electrical distribution, a house or working circuit, a switch controlling the same, magnets or solenoids for operating the switch,a derived orlocalized source of energy connected with the said working circuit, a wattmeter operated by the said source when energized, a spring-contact mounted on the counter of said wattmeter and connected to one of the wires of the system, and an adjustable contact-bearing spacing-wheel having contacts. cooperating with the said spring-contacts, the adjustment of the said spacing-wheel being under the control of a coin as set forth, and each contact on the spacing-wheel being adapted to be connected through one of the switch-operating magnets or solenoids to a separate wire of the system.

5. In a system of electrical distribution, a prepayment-wattmeter comprising a counter carrying a movable contact, a spacing-wheel carrying cooperating contacts, a lever adapted to actuate the said spacing-wheel a definite distance, and a coin-duct adapted to carry the coin into contact with the said 1ever, the movable contact being connected with one side of an electric circuit and each of the cooperating contacts being connected with the other side of the system through a magnet or solenoid, as set forth.

6. In a prepayment-wattmeter, a counter carrying a contact which is connected with the neutral wire of the three-wire system, a spacing-Wheel carrying two cooperating contacts, each connected with one of the mains of the same system, a normally open switch interposed between each of the last-named contacts and the mains, and means brought into operation by a weight or coin for closing these switches alternately, whereby the three wire system is first brought into operation by the action of the coin and afterward thrown out of operation at the expiration of a predetermined period.

7. In a prepayment-wattmeter, a counter, a pair of contacts, means for adjusting the said contacts along a circumference concentric with the counter, a trailing contact carried by the counter, a suitable switch, and circuit connections whereby the switch is operated on the initial contact of the trailer and one of the said contacts, and suitable circuit connections whereby the switch is operated in a reverse direction after a predetermined period when the trailer strikes against the second contact.

8. In a prepayment-wattmeter, a counter, a pair of contacts, means for adjusting the said contacts along a circumference concentric with the counter and closing an electric circuit, a trailing contact carried by the counter and cooperating with one of the said contacts for closing the said circuit, and means operated by the normal movement of the saidcounter and its attached trailer for an independent circuit.

Signed at New York, in the county of New York and State of New York, this 26th day of July, A. D. 1901.

GEORGE G. TILDEN.

closing Witnesses:

GEORGE I'I. STOCKBRIDGE, WM. I-I. CAPEL. 

